Refrigerating apparatus



L. U. LARKIN July 18, 1944.

REFRIGERATING A PARATUS ets-Sheet 1 7 Original Filed March 19, v1938 2She 4+- m /d {INVEN/TOR,

-14; ATTORNEY.

July 18, 1944. L. u. LARKIN REFRIGERATING APPARATUS Original Filed March19, 1938 2 Sheets-Sheet 2 i z 'fl 1 m, 4:510 Q l 56 g Qi p Q12!) 5 a611'!) QIID g pads KINVIENTOR,

A54, ATTORNEY.

Patented July 18, 1944 oar-loaaarmoaaarmc APPARATUS Lester U. Larkln,Chicago, 111., assignor to Lul Products, Inc., Baltlm of Maryland ore,Md., a corporation Original application March 19, 1938, Serial No.196,881. Divided and this application August 28, 1941, Serial No.408,564

2 Claims.

The present application is a division of my copending application SerialNo. 196,881, flled on March 19, 1938, which has become Patent No.2,258,618, issued October 14, 1941.

My invention relates to the art of heat exchange, and more particularlyas involved in refrigeration.

One of the objects of my invention is to provide an improved heatexchanger coil suitable for use as an evaporator, including sectionalend plate supporting structure and an improved arrangement for securingthe sections of the end plate structures together.

Refrigerated show cases, such as are used in retail stores, aremanufactured in a great variety of sizes and shapes. As a rule, the showcase itself and the refrigerating apparatus are manufacturcd bydifferent concerns, and while that portion of the apparatus consistingof the motor compressor, condenser and controls may be more or lessstandardized, the evaporators must be furnished in many difl'erent sizesor shapes in order to be accommodated properly within the different showcases. In accordance with my invention an evaporator coil of practicallyany dimensions maybe fabricated from standardized parts.

Further objects and advantages of my invention will be apparent from thefollowing description considered in connection with the accompanyingdrawings, which form a part of this specification, and of which:

Fig. lis a perspective view of a completed coil in accordance with myinvention;

Fig. 2 is a cross-sectional view'on an enlarged scale taken on the line2--2 of Fig. 1;

Fig. 3 is a cross-sectional view taken on the line 3-3 of Fig. 2;

' Fig. 4 is a cross-sectional view taken on the line 4- 4 of Fig. 3;

Fig. 5 is an enlarged cross-sectional view of a portion of the deviceshown in- Flg. 4;

Fig. 6 is a view similar to Fig. 5, but showing certain parts indifferent position;

Fig. 7 is a side-view of a tool employed in the construction of the coilshown in Figs. 1 through 6- r Fig. 8 is a cross-sectional view taken onthe line 8--8 of Fig. 7;

Fig. 9 is a cross-sectional view taken on the line 9-9 of Fig. 7;

Fig. 10 is a cross-sectional view takenv on the line Illl0 of Fig. 7;and

Fig. 11 is across-sectional view of a different form of coil.

Referring more particularly to Figs. 1 through 6, reference characterIll designates generally a pipe coil consisting of straight tubes I2,all except two of which are connected at opposite ends to adjoiningstraight tubes by means of return bends I4. One end of two of thestraight tubes is provided with a flared fitting [6, by means of whichthe coil may be connected to the suitable conduits leading to the usualcompressor and condenser.

Secured in heat transfer relation to the straight tubes I2 is aplurality of closely spaced heat transfer fins l8. As shown, each fin issecured to two adjacent tubes, which are connected together by a returnbend I 4, the fins being provided with openings through which the tubesextend. Each pair of tubes to which the same fins are attached, togetherwith the return bend connecting the tubes together, constitutes what mayconveniently be termed a hairpin. While the flns may be secured on thetubes in any desired manner, a preferred method and apparatus foraccomplishing this is described and claimed in my above mentionedapplication Serial No. 196,881, of which this application is a division,as well as in another divisional application, Serial No. 404,105, flledon July 26, 1941.

A complete evaporator coil consists of any desired number of hairpinsjoined together and supported in end plates 20, as is shown in Fig. 1.The end plates 20 are made up of a plurality of sections, including alower section 22, an upper section 24, and intermediate sections 28.lower section 22 is formed with an out-turned flange 28 along its loweredge and an inturned U-shaped flange 30 along its upper edge. Each ofthe intermediate sections ls formed with an inturned flange 32. Atequally spaced points along flange 32, ears 34 are provided. U-shapedflange I0 is provided with apertures '36 at similarly spaced points. Theupper edge of each of the intermediate sections 26 is formedwith aU-shaped flange :oa, similar in all respects to the flange on the lowersection. The lower edge of upper end section 24 is formedwith aninturned flange similar in all respects to the flange 32 formed on thelower edges of section 26. Upper section 24 is also formed with anout-turned flange 28a, similar to flange 28 on the lower end section.Each of the intermediate sections is formed with substantiallysemi-circular openings along their mating edges, while the lower section22 is formed with such openings along its upper edge and the upper section 24 is formed with similar openings along its lower edge. The radiusof these openings is Substantially equal to the radius of the tubesforming pressed toward each other.

located at one end of the coil, the opposite ends. 7

An intermediate section is then put in place by slipof the tubes beingas yet unconnected.

ping the flange 32 thereon between the legs of the U-shaped flange 30 inthe lower section, and

with the ears 34 extending through the apertures 36, as is shown in Fig.5. The next step is to bend-the ears 34 tothe position shown in Fig. 6,and for this purpose a'tool shown in when it is drawn into place betweenthe legs of the u-shaped flange 30, it pulls the sections 22 and 26together. Inasmuch as the openings in the edges of these sections areslightly less than semi-circular, when they a ie. pulled together theedges of the openingsuare securely clamped around the tubes which extendtheret'hrough.

Thereafter, another row of hairpins is placed in the'openings in theupper edge of the intermediate section and another intermediate sectionof end plate is secured thereto in the same manner as just'described.This is repeated until Fig. 7 is provided; This tool includes avertical-' ly extending arm '18 rigidly secured to which is a.

handle 4|). Pivotally mounted on arm 38 at 42 is a member 44 havingparallel guide channels 46 extending downwardly on one side of arm 38,and an arm 48 extending 'downwardly'on the other side. Slidably mountedin channels 46 is a bending bar 'orplunger "the upper end of whichextends above the guide channels and is normally held in a raisedposition by means of one end'of a spring 52, which spring'is wrappedaround the pivot 42. The other'end of the spring engages arm 48 andtendsto rotate the arm in a clockwise direction as viewed in Fig. "I.Pivotally secured to the upper end of the arm 38 at 56 is a cam 58integral with a handle 60. The face of cam 58 bears against the upperend of bending arm 50 and, when the cam is rotated, forces the bendingbar downwardly against the force of spring 52. A handle 82 is pivoted toarm 38 at 31 and has an arm 6i contacting the inner side of arm 4!.

'a coil of the. desired size has been assembled,

whereupon an upper section 24 is fastened in place. A sufllcientnumberof return bends i4 are applied tothe free ends of the hairpins, bysoldering them thereto, thus connecting the various hairpins together inthe manner shown in Fig.1. Flared fittings Ii] are applied to the freeends'ofthe coil, and provide meansforconnecting the evaporator coilin arefrigerator system.

In the coil shown'in Fig. 1, theflns on all the'hairpins forming thecoil extend in the same direction. However, this is not essential andacoil may be made'up in other ways, for instance as shown in Fig. 11,wheresome of the .ilns are-horizontal while others are'vertical. .Thus acoil-of almostany proportions maybe fabricated.

It is to be understood that the foregoing description has been given forpurposes of illus- In operation, the .above described t'oolis ap-" pliedto the two sections of the end plate which are to be secured together,in'the manner'shown in Fig. 7, that is, with a bearing face 68 of arm IIin contact with the outer surfaces of 1 the two sections. Guides 46extend downwardly on the inside of the plates and, by squeezing handies'40 and 82 together, arm 48 is rotated in a counter-clockwise directionso as to bring guides 46 against the inner edges of the U-shaped flangesand 30a. The tool is so located that the ear 34 extends between the twoguide channels 48, the lower' end of the bending bar Bil being above theear. Thereupon, handle 60 is rotated in a clockwise direction, as viewedin Fig. 7, so

as to cam the bending bar 50 downwardly. 'During this movement arms and62 are held 7 The lower end of bar 50 strikes the ear 34 and bends itfrom the position shown in Fig. 5 to that shown in Fig. 6, In this bentposition, the earsecurely fastens the two sections of the end platetogether.

As is shown in Figs. 5 and 6, flange is'dlsposed at slightly less than90 with respect to the front surface of the plate. Consequently,

tration only as showing preferred embodiments of the-various structuresin accordance-with my invention, as, is required by the patent statutes.It is not, to be considered as limiting the scope of my invention, whichis to be-determined by the appended'claims. r

, What is claimed is:

1. End plate structureior a tubeheat exchanger including apluralityofsections having edges meeting along the centerlines of the tubes, the

edge of one section being i'ormed with a U- shaped flange havingspacedapertures, and the adjacent edge of. an adjacent section beingformed with, a flange adapted to berreceived within said U-shaped flangeand with projections adapted to extend through said apertures.

2. A heat exchanging unit having parallel rows of pipes, a supportingstandard for said pipes including a series of plates extendingsubstantially atright angles to said pipes, and means for detachablyconnecting adjacent plates together including a flange on'the edgerofone plate bent over a flange formed on the edge of the adjacent plate,the first named flangebeing provided at its return bend with a series ofspaced apart slots, the second named flange having tabs prosecure saidplates-t0 each'z-other.

LESTER U.

